You're in a ten man squad of Space Marines, and you are infiltrating an enemy spaceship. You will split into two five man teams (only one team needs to be filled for us to start). One team will infiltrate through a hull breach, slice through a wall, and head to the command deck to capture the ship's Captain. The other team will infiltrate through a missile port and sabotage the weapon's system. Further instructions will be given upon the successful completion of this mission.
This is all part of a larger space battle taking part among dozens of ships. The mission only truly fails when all players are dead, at which point we will simply start all over again with a new squad conducting the same plan on a different battleship in the battle.
You are badass space marines, so 5 enemies (rounded up) are worth 1 of you. For every 5 enemies, somebody in the squad (picked based on the narration or randomly (usually the latter)) must roll for defense.
On defense, rolling 2 or 3 is a hit. 4, 5, or 6 are all misses. A 1 is a hit for double damage. Getting hit brings you to damage.
When taking damage, rolling a 1 means you take damage and are stunned for a round, rolling a 2 means you take damage but are not stunned. Taking damage triggers a reflexive roll. On a 1, you take 5 points of damage. On a 2, you take 2. On a 3, 4, or 5, you take 1. On a 6,your armour absorbs all possible injury/you are a badass and shrug it off, no sweat.
When attacking, rolling a 6 means you carve a path in the flow of defending Marines, bringing you much closer to victory. A 3, 4, or 5 means you only kill one of them, oh well. A 1 or 2 is a miss, with the 1 meaning your accelerator assault rifle runs out of ammunition and you need to put in a new clip. Sometimes you will come across bosses, such as enemy Commanders or giant robots who will have hit points just like you!
You get 10 hit points. Once you run out, you die. Other things can kill you as well.
There are five 'classes' of Space Marine. None of them have any real disadvantages, but they all have small advantages, and some of them are kind of important (like the Medic, or the Techie!), though not absolutely necessary to mission success. Each of the five man teams has one of each class. They are:
Squad Leader: Whenever he's around, if his buddies roll a 1, he can roll a die to fix this problem. If he gets a 6, then his buddy's roll is actually a success! 3, 4, or 5 means the roll is only a regular failure. 2 means that the 1 is still horrible. 1 just makes things worse.
Special Weapons Officer: He kills twice as many dudes. So instead of one Marine dying, he kills TWO! When fighting bosses, he instead does twice the amount of damage.
Medic: The Medic can roll a die to heal his friends. This takes a few minutes to do, so it should be done while the squad is relatively safe. On a 6, his friend is fully healed (Back to 10 hp!). On a 3, 4, or 5, the friend heals 2 hit points. On a 2, the friend heals 1 hit point. On a 1, the Medic does more harm than good and deals 1 damage.
Techie: Everybody can try to hack into doors, or weld them open, or set up explosives, but they only succeed on a 4, 5, or 6. The Techie only fails to do so on a 1!
Squaddie: He never really had a specialty, but he gets 12 hit points instead of 10.
We only need to fill up one squad to start the game. Filling up both means that both squads are moving simultaneously. Filling up only one means that both squads are moving simultaneously but one of the squads is full of NPCs until somebody signs up for them. Sign up by supplying your first and last name, perhaps some sort of callsign if you wish, and maybe a short description of your Space Marine. Then, grab a rank and class.
First person to sign up chooses the mission, since I'd prefer if we filled up one before going for the other.
Squad Alpha (Attacking the Bridge)
Major Desmond "Blackjack" Orange (Squad Leader)
Sgt. Avery Johnson (SWO)
Cpl. Helcion "Wolf" Child (Techie)
Pvt. Milo Minderbinder (Medic)
Pvt. Vert Igon (Squaddie)
Squad Beta (Sabotaging the Weapons)
Lt. Matan "Ghost" Jetsquirrel (Squad Leader 2)
Sgt. Greggory McGreggorson (SWO) - DEAD (Shot to death by enemy Marines outside a missile tube)
Cpl. Sturgeon Wickerblade (Medic)
Pvt. Urist Boozebrain (Techie)
Pvt. George "Snap" McRipper